Prepare the cake: Poke holes all over the tops of the 2 cake layers using a toothpick. Brush the cakes with the pineapple juice, letting it soak into the holes; set aside.
Make the filling: Bring the dried pineapple, pineapple juice, cream of coconut and 1/2 cup water to a simmer in a medium saucepan over medium heat. Cook, stirring occasionally, until the dried pineapple is soft and the liquid is reduced to a thick syrup, about 20 minutes. Let cool, then mash with a potato masher to make a chunky jam.
Make the frosting: Beat the butter and salt in a large bowl with a mixer on medium speed until smooth and fluffy, 1 to 2 minutes. Gradually beat in the confectioners' sugar until smooth. Add the cream of coconut, increase the mixer speed to medium high and beat until thick, 2 to 3 more minutes. Assemble the cake: Place 1 cake layer on a platter; spread the pineapple filling on top, stopping about 1/2 inch from the edge. Top with the second cake layer and press down gently. Cover the whole cake with the coconut frosting. Top with the toasted coconut and dried pineapple.
Basic Vanilla Cake
Preheat the oven to 350 degrees F. Butter two 9-inch-round cake pans and line the bottoms with parchment paper; butter the parchment and dust the pans with flour, tapping out the excess.
Whisk 3 cups flour, the baking powder and salt in a bowl until combined. Beat 2 sticks butter and the sugar in a large bowl with a mixer on medium-high speed until light and fluffy, about 3 minutes. Reduce the mixer speed to medium; beat in the eggs, one at a time, scraping down the bowl as needed. Beat in the vanilla. (The mixture may look separated at this point.)
Mix 1/2 cup water with the cream in a liquid measuring cup or bowl. Beat the flour mixture into the butter mixture in 3 batches, alternating with the cream mixture, beginning and ending with flour, until just smooth.
Divide the batter between the prepared pans. Bake until the cakes are lightly golden on top and the centers spring back when pressed, 25 to 30 minutes. Transfer to racks and let cool 10 minutes, then run a knife around the edge of the pans and turn the cakes out onto the racks to cool completely. Remove the parchment. Trim the tops of the cakes with a long serrated knife to make them level, if desired.